In Brief:
Most cortical evoked potential studies typically use only one sound (short duration clicks, tones, and synthesized speech tokens (e.g., /da/)) to test all subjects. A limitation of this approach is that /da/ might not be representative of the types of perceptual errors made by all individuals tested. Consequently, when group comparisons are made, between normal hearing and cochlear implant (CI) listeners for example, individual variability is not reflected. We therefore set out to determine if different naturally produced speech sounds evoked distinct neural response patterns in individual CI listeners, and if the evoked patterns can be reliably recorded, from one session to another. Using a repeated measures design, acoustic change (P1-N1-P2) responses were recorded from participants wearing Nucleus-24 devices. CI listeners were tested and retested within a 3-wk period using two different naturally produced speech syllables. Results demonstrate that naturally produced speech stimuli evoke distinct neural response patterns in individual CI listeners. Moreover, these unique patterns can be reliably recorded in individuals, from one session to another. For these reasons, we believe acoustic change responses have the potential to be used to examine the neural detection of time-varying cues in individuals who wear cochlear implants.
